How much yeast is this?

Hello all, I recently read an article about proper pitching rates and it's converted me. I used to reuse a yeast cake a couple times or simply make a starter with no real attention to how big it was, and while everything has worked out fine thus far for my 2.5 gallon batches, I'd like to put a bit more effort into the amount of yeast I use. I found the popular pitching rate calculator at MrMalty.com, but it's asking some questions about my slurry that I'm not sure about. Here's what I have of my San Diego Super Yeast that I harvested on 8/24 and want to use this weekend for a 1.076 OG stout:

The calculator wants to know where this falls on a spectrum from "thick" to "thin" and it also wants to know how much non-yeast material is in there. I have no idea how to answer either, so I'm not sure what degree to build this up to. An eyeball estimate tells me this is roughly 40ml of packed yeast at the bottom, but now what? Anyone familiar with these characteristics that can help me out?